Air-compressor



(ModeL) I G,- MONSON.

. AIR COMPRESSOR.

No. 257,885; Patented-May1v6,-1882.

B A I)! I'D! WITNESSES. I INVENTEIRI PATENT Quince,-

CHARLES MoNsomoF new HAVEN, counnorrour.

AIR-COMPRESSOR.

SPECIFICATION forming To all whom itmay concern Be it known that I, CHARLES MoNsoN, of

Q the city and county of New Haven, in the State of Connecticut, have invented a new and useful Improvementin Air-Compressors and I hereby declare the following to be a specification thereof, reference being had to the accompanying drawing, which is a central vertical section of my invention.

My invention relates to the general subject of air-compression; and it consists of one or more cylinders or air-pumps wherein the common atmosphere received fromwithout through suitable valves is forced by a piston into the central chamber or reservoir of compressed air, and passes therein through valves of said chamber, which are alternately relieved from the re sistingpressureof the compressed airby means of favorable currents produced at the entryports by cylinders and pistons connected with said chamber, for the purpose as hereinafter more fully specified. .The usual methods of compressing air are attended with this difficulty, that the pressure of the compressed air is continually increasing within the reservoir during the operation of pumping, until the pressure is so great as to efi'ectually close the valves against the admission of any more air. Hencea continualincrease of power is required to move the pump, until at length no reasonable degree of power is able to force open the valves of the chamber against the accumulated pressure of the air confined therein. This difficulty is obviated by my invention. Whereas in air-compressors as hitherto constructed the pressure is against the valves to resist the en-- trance of new accessions of air, I have discovered that this resistance may be overcome by causing currents of the compressed air itself (or other fluid under pressure) to so move at and away from the entry-ports that the valves there placed are wholly relieved from the pressure of the compressed air within the chamber and readily open to the new air under pressure of the piston of the air-pump.

In the drawing, A represents the central air chamber or reservoir for compressed air, (or other fluid or fluids under pressure.) Cylinders B B are connected therewith on each side, opening into the chamber by the small ports a part of Letters Patent No. 257,885, dated May 16, 18812. Application filed March 26,1881. (Modeh) a at the top of the cylinders and the large ports .b b at the bottom.

In the cylinders B B are the pistons C G,

moving reciprocally and operated by power applied to a walking-beam. The cylinders B B and the chamber A contain compressed air only, (or other fluid under; pressure.)

p The cylinders D D above. the pistons are connected with the cylinders B B, respectively, and within them move reciprocally the pistons E E, operated by power appliedto said walking-beam. The cylinders D D communicate at the top with the cylinders B B by the small ports 0 0, and at the bottom they communicate with the chamberA by the lon g ports at d". Flap-v. valves 6 e at the bottom of the cylinders D D admit the outer air as the pistons EE respectively rise.

A shuttle-valve, F, is supported and has a sliding movement within the standard G atthe bottom of the chamber A. It has at the ends the conical heads f f, which fitinto seats of corresponding'shape at the inner ends of the ports 61 d, as shown inithe drawing. These cone-valves, if the cone is enlarged at its outer or smaller end, will take increased force from the currents of both ports I) (1.

Having thus specified the construction of' my improved air-compressor, I proceed to explain the method of its operation, Suppose the chamber A to be filled with compressed air. This air will also fill the cylinders B 13',

thecylinders D D above the pistons E EQ The chamber and cylinders have free and constant communication through the ports a a b b c 0'. Now apply power to reciprocate the pistons O 0. Suppose the piston G to be descending and the piston G to be ascending.

A current of compressed air (or other tluid) is driven downward in the cylinderB, out through the port I) into the chamber A, and drawn in through the port I), up under the piston O" of the cylinder B, and also from above the pistonO a current of compressed air is flowing.

out through the port a into the chamber A, and through the port o-into the cylinder or, in other words, this movement of the pis-- tons is causing the compressed air to flow from left to right at the bottom of the chamber and from right to left at the top of the chamber. Now, simultaneous with this movement of the pistons O G and the consequent currents of compressed air, as described, the pistons E E are moving reciprocally, being operated by power, the former descending and the latter ascending in the cylinders D D, respectively. The air, filling the lower part of the cylinder D under its piston, (being at the natural pressnre,)descends as driven by the pistonE, and, being prevented from escaping'into the outer air by the closing of the flap-valve 0, passes through the port d, and, impinging upon the end of the valve-head f, crowds it from its seat, and at the same time causes the valvehead f to be seated at the opposite end of the shuttle-valve F. This air rushes past the valve-head fand joins and mingles with the current of compressed air which is flowing at the same time, as-above described, in the same direction through the port 1) into the chamber -A. The new air 'is thus imprisoned in the chamberA, and cannot escape, because assoon as the movements of the pistons E E are reversed the valve-head f isagain seated, and prevents egress, and the new air must mingle with the volume-of the compressed air, still further compressing it. As the piston E ascends the flap-valve 0 opens and the outer air rushes in to fill the lower part of the cylinder D under the piston E but when the piston E descends the flap-valve c closes and this new air is forced into the chamber A, in the same manner as above described.

In this manner the volume of the com pressed air, which in all other compressors opposes the entrance of new air, is compelled to move in currents facilitating such entrance, and the result is that I can obtain a'higher degree of compression at the cost of less power, and, being provided with comparatively a moderate amount of power, I need no increase of it. For example, itneeds but little power to move down the piston E, for the common air which is driven downward by it has a powerful current of compressed air ready at the port d to escort it into the chamber A. The twin piston E will be prompt to rise, being sure of a place ready made for its discharge in chamber A, for as fast as the piston'E descends it makes room in the chamber A for the piston E todischarge into. The pistons O U E E must yield to the power externally applied. Till then all are motionless. The still repose of pressure force is there; but it is a balanced pressure; but any movement of the pistonsunbalances that pressure, and the pressure in the direction of the movement of the piston-s preponderates by precisely so much as the amount of the added power which has been externallyapplied. Bccauseof thepressure of the compressed air one-half is already in favor of the movement and one-half is opposed to the gree of the pressure within may be.

movement. This results from thelaw of fluidpressure, and is equally true whatever the de- This is a novel and useful feature of my invention. I balance the pressures of the compressed air between movable diaphragnis or pistons of equal surface-pressures, which balanced press-v ures may be unbalanced at will in either direction by the application of external power to a lever or walking-beam operating such diaphragins or pistons. As the pressure 1s uni- ;form throughout the chamber A and on, each ,side of the pistons in the cylinders B B, the pressure of the compressed air in favor of the movement is exactly equal to the pressure opposing it, whatever the degree of the pressure may be, and a moderate outlay of external power can easily move the pistons, and the practical result is the creation of currents of any desired velocity or force within the chamber and its ports, as above described.

Another novel and useful feature of my invention isthe arrangement of the ports a a c c, by which I am able to charge the descending pistons E or E (as the case may he) with compressed air direct from the chamber A time after time-,whatever the degreeofthe com- 1 pression of said air may be, whereas in all other aircompressors the air-pum pisworkin gaga-inst acontin uall y and intensely accumulating pressure of the con-fined air.

By my device that very pressure is made to assist the downward movement of the piston of the air-pump and to force the new installments of the external air (that was) from beneath the piston E (or e E) into thecentral reservoir.

It is obvious that this method is'equally applicable to other fluids than air, or to other fluids with air, and useful results may be obtained by partially filling the chamber with water to produce strong currents at the ports I) b alternately to facilitate the entrance of the new air. It is also obvious that the principle which I claim may be embodied in other de vices beside the one above specified-as, for example, I may use, instead of or as well as V pistons to create the fluid movements, a rotating chamber, or rotation within a chamber,

1 which may be partially filled with water, and air and water currents may be formed therein (the water being under the air-pressure) by the centrifugal force generated in the denser fluid as the chamber (or other rotary) revolves; but

any such variation of device would be within my invention, an essential principle of which is the formation of fluid-currents in the reservoir of compressed air, into which currents the newair is taken and made to flow in the Pat- ' the cylinder D, disch argingnatural air through its port at into the air-chamber A by'means of its piston E, said pistons descending simultaneously within their respective cylinders for the purpose of injecting a current of natural air into a current of com pressed air while both currents are moving in the same direction, substantially as specified.

2. The combination of the air-chamber A, the cylinders B D, the pistons G E, the ports a b c d, and valve e, to facilitate the descent of the piston E in its cylinder D by the pressure 

